Tetrahedrite

It is the antimony endmember of the continuous solid solution series with arsenic-bearing tennantite.

Other elements also substitute in the structure, most notably iron and zinc, along with less common silver, mercury and lead.

Bismuth also substitutes for the antimony site and bismuthian tetrahedrite or annivite is a recognized variety.

Tetrahedrite occurs in low to moderate temperature hydrothermal veins and in some contact metamorphic deposits.

[3] The now-defunct company Alphabet Energy announced plans to offer a thermoelectric device based on tetrahedrite to turn heat into electricity.